Characterization of the carbohydrate chains of the secreted form of the human epidermal growth factor receptor

Glycobiology. 2000 Sep;10(9):901-17. doi: 10.1093/glycob/10.9.901.


The human epidermal growth factor receptor (EGFR) is a transmembrane glycoprotein having 11 potential N-glycosylation sites in its extracellular domain. N-Glycosylation is needed for proper membrane insertion, EGF binding and receptor functioning. The human epidermoid carcinoma A431 cell line secretes a soluble 105 kDa glycoprotein (sEGFR) that represents the extracellular domain of the membrane-bound form, and its glycosylation pattern has been investigated. After liberation of the oligosaccharides from sEGFR with PNGase F, the glycans were fractionated along different routes, including Concanavalin A affinity chromatography, anion-exchange chromatography, HPLC and high-pH anion-exchange chromatography. The oligosaccharide fractions were characterized by 500- and 600-MHz 1H-NMR spectroscopy and mass spectrometry (FAB, ESI, and MALDI-TOF). The oligomannose-type glycans range from Man5GlcNAc2 to Man8GlcNAc2 and account for 17% of the total carbohydrate moiety. Furthermore, di-, tri'- and tetraantennary complex-type structures are present, both neutral and (alpha2-3)-sialylated (up to tetrasialo), comprising 24 and 59%, respectively, of the total carbohydrate moiety. In this study, 32 new complex-type glycans are characterized containing the Le(x), Le(Y), and sialyl-Le(x) determinants, the bloodgroup A and H antigens, as well as the ALe(Y) determinant. This first comprehensive glycosylation study on a human nonrecombinant receptor shows the immense heterogeneity of the glycosylation of sEGFR.

MeSH terms

  • Amidohydrolases / metabolism
  • Carbohydrate Conformation
  • Carbohydrate Sequence
  • Chromatography, Affinity
  • Chromatography, High Pressure Liquid
  • Chromatography, Ion Exchange
  • ErbB Receptors / chemistry*
  • ErbB Receptors / genetics
  • ErbB Receptors / isolation & purification
  • ErbB Receptors / metabolism*
  • Glycosylation
  • Humans
  • Magnetic Resonance Spectroscopy
  • Membrane Glycoproteins / chemistry*
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / isolation & purification
  • Membrane Glycoproteins / metabolism*
  • Methylation
  • Molecular Sequence Data
  • Oligosaccharides / analysis*
  • Oligosaccharides / chemistry*
  • Oligosaccharides / metabolism
  • Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase
  • Solubility
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
  • Tumor Cells, Cultured


  • Membrane Glycoproteins
  • Oligosaccharides
  • ErbB Receptors
  • Amidohydrolases
  • Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase